Forest City, Illinois, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, hazelnut, lavender, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Forest City, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Forest City lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Forest City — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Forest City — the short answer
Forest City, Illinois: USDA zone 6a, about 206 days between hard freezes, across 335 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~206
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 335 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 6a is Forest City's average, not your lot's — a low corner or a tree line moves it. Against Forest City's 206-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Forest City
Each reading below is measured for Forest City itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredForest City runs about 206 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredForest City sits in USDA hardiness zone 6a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Forest City is in
Forest City sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Forest City's own centroid rather than borrowed from Mason County.
What Grows in Forest City
Every plant below cleared Forest City's own zone 6a and its 206-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Forest City?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 28 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
What's on the federal record near Forest City
Closest first, within ~10 miles of Forest City. Listing isn't leaking, and distance isn't exposure.
- Forest City TownshipUnderground Storage Tanks · 1200 ft
- Rickett Grain CoUnderground Storage Tanks · 1400 ft
- Sand Ridge State Forest HeadqUnderground Storage Tanks · 1500 ft
- State Bank Of HavanaUnderground Storage Tanks · 1500 ft
- GarlischrichardUnderground Storage Tanks · 1500 ft
- FOREST CITY HIGH SCHOOLSuperfund · 1600 ft
- MICHELS PIPELINEBrownfields · 0.5 mi
- Ditch Rd and 2100 NNitrate · 1.4 mi
- 2300 N and 2750 ENitrate · 2.1 mi
- 2450 E and 2000 NNitrate · 3.6 mi
- Midwest Central School Dist 191Underground Storage Tanks · 3.9 mi
- United SalesUnderground Storage Tanks · 4.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Forest City's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Forest City.
Total Sites
88
within ~10 miles of Forest City
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Forest City
Severity Distribution
within ~10 miles of Forest City
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Forest City, Nitrate runs higher than the national average — 46 sites within ~10 miles of Forest City. That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Forest City
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Forest City average
Your land is one point inside Forest City
Everything above resolves to Forest City as a whole — one PHZM band and one 28°F frost record, read across 335 acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Forest City Average
Forest City Average
- ●USDA Zones 6a, averaged across Forest City
- ●One soil character for all of Forest City
- ●Frost dates read at Forest City's scale: Apr 5 to Oct 28
YOUR Parcel
- ✓Your exact zone, not Forest City's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Forest City
Pull a site-specific report for your exact address in Forest City, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Forest City averages can't show:
We read public map data around Forest City — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Forest City average
How we know this about Forest City
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Forest City’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Forest City
When does frost risk typically end in Forest City?
The last hard freeze (28°F) in Forest City typically lands around Apr 5, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 26.
When is the first frost in Forest City?
The first hard freeze (28°F) in Forest City typically arrives around Oct 28, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 14, so the watching starts about Sep 28 — about 206 days after the spring freeze cleared.
How long is the growing season in Forest City?
Measured between 28°F hard freezes, Forest City sees about 206 frost-free days — roughly Apr 5 through Oct 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 26 to Oct 14, about 171 days.
Is the soil safe to grow vegetables in Forest City?
The federal record around Forest City is a meaningful one — 88 documented sites, mostly Nitrate entries (46), the nearest Underground Storage Tanks record about 0.2 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Forest City?
From about Sep 28 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Oct 28 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Oct 28. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Forest City's scale — its 6a band and its 206-day season. Your yard writes its own version of Forest City's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Forest City’s own scale
6 of the readings below were taken at Forest City's own scale — its own ~206-day season between 28°F freezes, the 335 acres it covers and 88 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Forest City's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Forest City's own 28°F hard-freeze dates, about Apr 5 and Oct 28 and the ~206-day span between themNOAA 1991–2020 Climate Normals
- 88 documented contamination sites on the federal record near Forest City, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Forest City's boundary and the 335 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~206-day seasonGrowable Ground crop-matching engine
- The ecoregion at Forest City's own centroid, the Central Corn Belt PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Forest City's 335 acres read through its county's SSURGO summaryfrom Mason County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Mason County
- The growing challenges every Illinois grower plans around — written at state scale, so they stay on the state guidefrom Illinois
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Mason County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Forest City's 335 acreswhy one lot differs from the next →
- Which side of Forest City you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 335 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Forest City-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisForest City sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides